3. Consider a pdf f so that a random variable X~ f has expected value E[X] = 3 and variance V[X] = 10. Now consider n = 10 i.i.d. random variables X1, X2,..., X10 drawn from f. Let X = 10 (a) What is E[X]? (b) What is VIX]? (c) What is the standard deviation of X? 10 ₁=1 Xi.

If a discrete random variable X has the following probability distribution: X      -2, - 1,     0,     1,      2 P(X) 0.2, 0.3, 0.15, 0.2,  0.15 Use this to find the following: (a) The mean of X and E[X^2]. (b) The probability distribution for Y = 2X^2 + 2 (i.e, all values of Y and P(Y )). (c) Using part (b) (i.e, the probability distribution forY ), find E[Y ]. (d) Using part (a), verify your answer in part (c) for E[Y ]. **Note: Please do not just copy from Chegg!

Suppose the lifespan (in months) of a smartphone battery can be modeled as a continuous random variable with CDF F(x) = 1 − e-x/3  x ≥ 0 What is the probability that the battery lasts between 12 to 15 months?

A researcher that wanted to estimate the expectation AY of a random variable Y got three independent observations, Y, Y, Y The researcher knows the value o, of the variance of Y and is considering the following estimators: Pi = 4) Yi + (+) ¥ Py = () Yn + (;) ¥½ + () Y½ in (}) Yi + (}) ¥z + (() %D Which of the following is correct? ONone of the above Ois an unbiased estimator of l and it has the smallest variance of the three estimators. Ois an unbiased estimator of µ and it has the smallest variance of the three estimators. O and i, are both unbiased estimators of fl and Var (ſîz) < Var (îì3). is an unbiased estimator of µ and it has the smallest variance of the three estimators.

True or False: For an exponentially distributed random variable, x, P(x) = 1/(b - a).

X is distributed as a Normal random variable with mean of 100 and a standard deviation of 10 (i.e X~N(100,10). You take a random sample of 20 items from X and you calculate the average of this sample. What is the expected value of this sample average? (i.e. what value would you expect to get for the average of this small sample?

1.) Consider the discrete random variable with pmf: P(X=x)=(A/(4^x)), x=2,3,4,5,.... What is the value of A?